When selecting a line for deletion, these errors appear, what is the problem?
enter image description here
private void button3_Click(object sender, EventArgs e)
{
con = new SqlConnection(#"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=E:\desk\new\abusalem\abusalem\Database1.mdf;Integrated Security=True");
cmd.Connection = con;
cmd.CommandType = CommandType.Text;
cmd.CommandText = "delete from datauser where id= "+dataGridView1.CurrentRow.Cells[0].Value;
con.Open();
cmd.ExecuteNonQuery();
con.Close();
filltable();
}
Here is a conceptual path to follow. The example is setup for a DataTable, if not using a DataTable but not setting the DataGridView.DataSource consider what is shown below. There is no need to reload the DataGridView once a row has been removed.
Setup a BindingSource scoped form level, set the DataSource to what you are using to populate the DataGridView currently e.g. a Datatable then dataGridView1.DataSource = someBindingSource. Set the primary key column to hidden so it is not seen.
If no primary key than adjust dataGridView1.CurrentRow.Cells[0].Value the code below to accept that value.
To remove a row, in the button click event. Here I have Id as the key.
public class Operations
{
private static string _connectionString =
#"Data Source=(LocalDB)\MSSQLLocalDB;" +
#"AttachDbFilename=E:\desk\new\abusalem\abusalem\Database1.mdf;" +
"Integrated Security=True";
public static bool Remove(int id)
{
using (var cn = new SqlConnection(_connectionString))
{
using (var cmd = new SqlCommand() {Connection = cn})
{
cmd.CommandText = "delete from datauser where id=#Id";
cmd.Parameters.Add("#Id", SqlDbType.Int).Value = id;
return cmd.ExecuteNonQuery() == 1;
}
}
}
}
Form code
private BindingSource someBindingSource = new BindingSource();
private void RemoveButton_Click(object sender, EventArgs e)
{
DataRow row = ((DataRowView)someBindingSource.Current).Row;
if (Operations.Remove(row.Field<int>("id")))
{
someBindingSource.RemoveCurrent();
}
}
In the future provide enough code so we have a idea what exactly is being done in regards to how the DataGridView gets loaded.
Related
i wanna do a combobox for the classes , when i insert the type of class in it i want to selecteditem the row that was selected exmple: i chose second row then i insert to the database a 2
sql = "insert into etudiant (Nom, prenom, sexe,classess) " +
"values(#Nom, #prenom, #sexe,#classess)"/*+"class (nom_class)" + "values(#nom_class) "*/;
cmd = new NpgsqlCommand(sql, conn);
cmd = new NpgsqlCommand(sql, conn);
cmd.Parameters.AddWithValue("#nom", bunifuMaterialTextbox1.Text);
cmd.Parameters.AddWithValue("#prenom", bunifuMaterialTextbox2.Text);
cmd.Parameters.AddWithValue("#sexe", bunifuMaterialTextbox3.Text);
int id = comboBox1.SelectedIndex + 1;
cmd.Parameters.AddWithValue("#classess",Int32.Parse(comboBox1.SelectedItem.ToString()));//*/
//cmd.Parameters.AddWithValue("Num", bunifuMaterialTextbox6.Text);
//cmd.Parameters.AddWithValue("Classess", bunifuMaterialTextbox7.Text);
int result = cmd.ExecuteNonQuery();
i couldn't find a way to do it like that
i wanna find a way so i can insert to table classes int for the number of that row like the ID
For your question, you would like to achieve the current combobox selected index and insert
it into your database.
First, I want to mention that you should use comboBox1.SelectedIndex instead of comboBox1.SelectedItem.
Second, I use sqlconnection to complete the same operation, so you can modify the following code to apply to your code.
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string connstr = #"";
SqlConnection connection = new SqlConnection(connstr);
connection.Open();
string sql = "insert into Example(Nom,Prenom,Sexe,Classess) values(#Nom,#Prenom,#Sexe,#Classess)";
SqlCommand command = new SqlCommand(sql, connection);
command.Parameters.AddWithValue("#Nom", textBox1.Text);
command.Parameters.AddWithValue("#Prenom", textBox2.Text);
command.Parameters.AddWithValue("#Sexe", textBox3.Text);
command.Parameters.AddWithValue("#Classess", comboBox1.SelectedIndex+1);
command.ExecuteNonQuery();
MessageBox.Show("add value successfully");
}
private void Form1_Load(object sender, EventArgs e)
{
comboBox1.Items.Add("class1");
comboBox1.Items.Add("class2");
comboBox1.Items.Add("class3");
comboBox1.Items.Add("class4");
}
}
I'm fairly new to C# and coding in general. I've looked through similar questions and didn't have much luck fixing this.
I am making an app that stores Student details for attendance in tables, in a database. Currently when I run it, the details are added to the tables from textboxes. A button opens a separate form with a datagridview, but the details are not updated in this. If I rerun the application and open the second form, the datagridview has been updated. How do I get the datagridview to update based on information added to the table while the application is running?
This is the code that adds the details to the table
using (SqlConnection sc = new SqlConnection())
{
sc.ConnectionString = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\corry\Desktop\StudentAttendanceBurton\Attendance.mdf;Integrated Security=True";
sc.Open();
using (SqlCommand com = sc.CreateCommand())
{
com.CommandText =
"insert into BUS102(\n" +
" Name,\n" +
" [Student ID],\n" +
" Date)\n" +
"values(\n" +
" #prm_Name,\n" +
" #prm_Student_ID,\n" +
" #prm_Date)";
com.Parameters.Add("#prm_Name", SqlDbType.NVarChar, 50).Value = student.Name;
com.Parameters.Add("#prm_Student_ID", SqlDbType.Int).Value = student.StudentID;
com.Parameters.Add("#prm_Date", SqlDbType.SmallDateTime).Value = student.Date;
com.ExecuteNonQuery();
}
}
This is the code for the form that has the datagridview
public partial class AttendanceForm : Form
{
public AttendanceForm()
{
InitializeComponent();
}
private void bUS102BindingNavigatorSaveItem_Click(object sender, EventArgs e)
{
this.Validate();
this.bUS102BindingSource.EndEdit();
this.tableAdapterManager.UpdateAll(this.attendanceDataSet);
}
private void AttendanceForm_Load(object sender, EventArgs e)
{
// TODO: This line of code loads data into the 'attendanceDataSet.BUS102' table. You can move, or remove it, as needed.
this.bUS102TableAdapter.Fill(this.attendanceDataSet.BUS102);
}
}
public partial class Form1 : Form {
private DataSet m_ds = new DataSet();
public Form1() {
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e) {
using (SqlConnection conn = new SqlConnection(#"Data Source=YOURSql;Initial Catalog=YOURDB;Integrated Security=True")) {
// set command
SqlCommand cmd = new SqlCommand("SELECT * FROM YourTable", conn);
SqlDataAdapter da = new SqlDataAdapter(cmd);
conn.Open();
da.Fill(m_ds);
// bind data to dataGrid
dataGridView1.DataSource = m_ds.Tables[0];
// refresh Data
dataGridView1.Refresh();
conn.Close();
}
}
private void cmdChangeData_Click(object sender, EventArgs e) {
// add new row explicit
DataRow nr = m_ds.Tables[0].NewRow();
nr[0] = "0000";
nr[1] = "xxxx";
// add new row to DataSet (just in memory, NOT TO DB)
m_ds.Tables[0].Rows.Add(nr);
// Refresh Data
dataGridView1.Refresh();
}
}
You have to refresh datagridview
this.dataGridView1.Refresh();
So I'm trying to create sort of an overview utility of sites, with different infos on each site.
I'd like to have a dropdown list / combobox, reading a sqldb and create items according to the db. Then I would like different textboxes to get populated with a value from a column.
Say my db table is called "AvSites" so far (just for the sake of it) i have "projectNr", "siteName", "siteClients" and "siteLicenses" columns I'd like each of these to populate some textbox / label somewhere.
I've tried the following, which kinda works, Ive had the code working most of the time, but the thing that defeats me is having the data change with the combobox item selected.
I hope you can help, and so here is my code so far (I have a login window, before this "main" program starts, just so you're not wondering)
And I'm quite new to C# so if there's something thats done inefficient thats the reason :) Im still learning.
namespace AvOverview{
public partial class frmMain : Form
{
public frmMain()
{
InitializeComponent();
}
private void Button1_Click(object sender, EventArgs e)
{
//btn_LogOut Click Event
this.Hide();
Form1 fl = new Form1();
fl.Show();
}
private void frmMain_FormClosing(object sender, FormClosingEventArgs e)
{
Application.Exit();
}
private void FrmMain_Load(object sender, EventArgs e)
{
string cs = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf";
SqlConnection con = new SqlConnection(cs);
con.Open();
string strCmd = "select * from AvSites";
SqlCommand cmd = new SqlCommand(strCmd, con);
SqlDataAdapter da = new SqlDataAdapter(strCmd, con);
DataSet ds = new DataSet();
da.Fill(ds);
combo1.ValueMember = "id";
combo1.DisplayMember = "siteName";
combo1.DataSource = ds.Tables[0];
combo1.Enabled = true;
this.combo1.SelectedIndex = -1;
cmd.ExecuteNonQuery();
con.Close();
}
private void Combo1_SelectedIndexChanged(object sender, EventArgs e)
{
string cs = #"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Database1.mdf";
string strCmd = "select id from AvSites";
SqlConnection con = new SqlConnection(cs);
SqlCommand cmd = new SqlCommand(strCmd, con);
con.Open();
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{//this last part is solely for testing if the text changed the way I wanted.
label1.Text = dr.GetValue(1).ToString();
label2.Text = dr.GetValue(2).ToString();
label3.Text = dr.GetValue(0).ToString();
label4.Text = dr.GetValue(3).ToString();
You don't need to call the database again. All the info are in the current selected item.
When you set the DataSource of your combo to a datatable like you do in the click event each element of the combo is a DataRowView and from this element you can get all the info extracted from the database from your initial query
private void Combo1_SelectedIndexChanged(object sender, EventArgs e)
{
DataRowView rv = Combo1.SelectedItem as DataRowView;
if(rv != null)
{
label1.Text = rv[1].ToString();
label2.Text = rv[2].ToString();
label3.Text = rv[0].ToString();
label4.Text = rv[3].ToString();
}
}
Side note: There are some improvements needed in your code.
First you should store the connection string in the config file and read it back with the ConfigurationManager class. Read about Configuration in NET
Second you shouldn't work with disposable objects like you do now. A disposable object should be disposed as soon as you have finished to use it. In particular the SqlConnection keeps valuable system resources both on your machine and on the server. You should start to use the using statement
string strCmd = "select * from AvSites";
using(SqlConnection con = new SqlConnection(.......))
using(SqlCommand cmd = new SqlCommand(strCmd, con)))
{
con.Open();
SqlDataAdapter da = new SqlDataAdapter(strCmd, con);
DataSet ds = new DataSet();
da.Fill(ds);
combo1.ValueMember = "id";
combo1.DisplayMember = "siteName";
combo1.DataSource = ds.Tables[0];
combo1.Enabled = true;
this.combo1.SelectedIndex = -1;
// ??? not needed ==> cmd.ExecuteNonQuery();
// not needed with using ==> con.Close();
}
// Here the connection is closed and disposed and resources are released
I have set up a listbox called lboxsupplier, i have also created a data adapter which i then used to populate the supplier listbox. When i run the form the listbox is empty. I want the listbox to populate with supplier ID and company which i will then click on to populate another listbox with products.
Namespace Pennyburn_Greg
{
public partial class FormProcess : Form
{
SqlDataAdapter daSupplier;
DataSet dsPennyburnGreg = new DataSet();
SqlConnection conn;
SqlCommand cmdSupplierDetails;
SqlCommandBuilder cmdBSupplier;
DataRow drSupplier;
String connstr, sqlSupplier;
public FormProcess()
{
InitializeComponent();
}
private void FormProcess_Load(object sender, EventArgs e)
{
connstr = #"Data Source= arlene-pc; Initial Catalog= PennyburnGreg; Integrated Security=True";
//dataAdapter for supplier listbox
sqlSupplier = #"Select* from Supplier";
conn = new SqlConnection(connstr);
cmdSupplierDetails = new SqlCommand(sqlSupplier, conn);
daSupplier = new SqlDataAdapter(cmdSupplierDetails);
daSupplier.FillSchema(dsPennyburnGreg, SchemaType.Source, "Supplier");
}
private void filllboxsupplier(string str)
{
daSupplier.Fill(dsPennyburnGreg, "Supplier");
lboxsupplier.DataSource = dsPennyburnGreg.Tables["Supplier"];
lboxsupplier.DisplayMember = "Company";
lboxsupplier.ValueMember = "SupplierID";
}
}
}
First of all, why are you calling FillSchema, rather should be calling Fill method to get the data, like
daSupplier.Fill(dsPennyburnGreg, "Supplier");
Once you have the dataset filled, then in your FormProcess_Load() you can add the dataset as datasource to the listbox like
lboxsupplier.DataSource = dsPennyburnGreg.Tables["Supplier"]
First thing you need to do is loosely couple your UI and data a little bit. Try this code:
// Returns a DataTable of ALL suppliers
private DataTable GetSuppliers()
{
return GetSuppliers(0);
}
// Returns a DataTable of the given supplier
private DataTable GetSuppliers(int supplierId)
{
using (var connection = new SqlCommand())
{
connection.ConnectionString = #"Data Source= arlene-pc; Initial Catalog= PennyburnGreg; Integrated Security=True";
using (var command = new SqlCommand())
{
connection.Open();
command.CommandType = CommandType.Text;
command.Connection = connection;
if (supplierId == 0)
{
command.commandText = "SELECT * FROM Supplier";
}
else
{
command.commandText = "SELECT * FROM Supplier WHERE SupplierId=#id";
command.Parameters.AddWithValue("#id", supplierId);
}
using (var adapter = new SqlDataAdapter())
{
using (var ds = new DataSet())
{
adapter.SelectCommand = command;
adapter.Fill(ds);
if (ds.Tables.Count > 0)
return ds.Tables[0];
}
}
}
}
return null;
}
And now you can just do this:
lboxsupplier.DataSource = GetSuppliers(int.Parse(lboxsupplier.SelectedValue));
lboxsupplier.DisplayMember = "Company";
lboxsupplier.ValueMember = "SupplierID";
Or if you need all Suppliers, just do this:
lboxsupplier.DataSource = GetSuppliers();
lboxsupplier.DisplayMember = "Company";
lboxsupplier.ValueMember = "SupplierID";
This code will provide some separation. This is still not ideal, but beats what you had.
You're not doing anything with the listbox control in FormProcess_Load, so it will be empty when it first loads. I'm assuming you have lboxsupplier_Click bound to the Click event of lboxsupplier? If so, then you'll need to click on that listbox before it will populate the Dataset (which is a very odd user experience, but if that's truly what you need...). If lboxsupplier_Click isn't an event handler, then you're going to have to manually call it.
If it still isn't populating, then try running your query against the database directly, and make sure that it returns data and has columns named "Company" and "SupplierID"
I have 2 datagridview controls in a Windows Forms application.
I would like to get the info of a person when I select first datagridview cell or row to next datagridview:
try
{
ConnectionStringSettings consettings = ConfigurationManager.ConnectionStrings["attendancemanagement"];
string connectionString = consettings.ConnectionString;
SqlConnection con = new SqlConnection(connectionString);
con.Open();
adap3 = new SqlDataAdapter(#"SELECT Date,Attendance,Remarks FROM dailyattendance where employee_id='"+DailyGV.CurrentRow+"'", con);
ds3 = new DataSet();
adap3.Fill(ds3, "dailyattendance");
dataGridView1.DataSource = ds3.Tables[0];
}
Im trying the above code. But it's not working.
I'm not too sure what DailyGV.CurrentRow is but basically you can use the RowHeaderMouseClick...see MSDN documentation. To use it, hook an event handler to it when initializing the form components (you can use VS designer as well...
dataGridView1.RowHeaderMouseClick += dataGridView1_RowHeaderMouseClick;
void dataGridView1_RowHeaderMouseClick(
object sender, DataGridViewCellMouseEventArgs e)
{
}
this event handler will get fired everytime you select a row header in the DataGridView control which will pass information about the event through an instance of the DataGridViewCellMouseEventArgs class (see MSDN documentation). This argument has a RowIndex property that provides the index of the row clicked which you can use to retrieve the values of the cells in that row...including the person id (if provided)...for example...
void dataGridView1_RowHeaderMouseClick(
object sender, DataGridViewCellMouseEventArgs e)
{
string personId = dataGridView1.Rows[e.RowIndex].Cells["PersonId"].Value;
//TODO: implement your own query to retrieve data for that person id
}
notice that you need to provide a proper column name when access the cells collection indexer...Cells["columnName"]
I will not give any description about the solution because Leo and Arsalan Bhatti has already suggested the solution. I am just telling you how your code should looks like and how it should be written.
string connectionString = consettings.ConnectionString;
using (SqlConnection con = new SqlConnection(connectionString))
{
try
{
con.Open();
string empID = DailyGV.CurrentRow.Cells["employee_id"].Value.ToString();
SqlCommand Cmd = con.CreateCommand();
Cmd.CommandText = "SELECT Date,Attendance,Remarks FROM dailyattendance where employee_id=#employee_id";
Cmd.Parameters.Add("#employee_id", SqlDbType.Int).Value = Int32.Parse(empID);
adap3 = new SqlDataAdapter(Cmd);
DataTable dt = new DataTable();
adap3.Fill(dt);
dataGridView1.DataSource = dt;
con.Close();
}
catch
{}
}
try
{
cn.Open();
string query = "select employee_id,Employee_Name,Image_of_Employee from Employee_Details where employee_id='" + dataGridView1.SelectedCells[0].Value.ToString() + "'";
SqlCommand cmd = new SqlCommand(query, cn);
SqlDataReader sdr;
sdr = cmd.ExecuteReader();
if (sdr.Read())
{
string aa = (string)sdr["employee_id"];
string bb = (string)sdr["employee_name"];
txtEmployeeID.Text = aa.ToString();
txtnameofemployee.Text = bb.ToString();
byte[] img=(byte[])sdr["Image_of_employee"];
MemoryStream ms=new MemoryStream(img);
ms.Seek(0,SeekOrigin.Begin);
pictureBox1.Image=Image.FromStream(ms); cn.Close();
}
}
catch (Exception e1)
{
MessageBox.Show(e1.Message);
}
You are passing the current row's index as employee id in SELECT query. Pass employee id for the selected record. Then it will work fine.